Kioptrix Level 1: A Penetration Testing Walkthrough

Introduction

As part of my cybersecurity learning journey, I conducted an initial security assessment of Kioptrix Level 1 in a controlled virtual lab environment.

The objective was to identify exposed services, investigate potential security weaknesses, analyze the collected evidence, and recommend appropriate remediation measures.

This article documents the reconnaissance process, web server misconfiguration, legacy cryptographic protocols, and historical vulnerability research. Findings are classified according to the evidence collected, and unverified exploitation claims are clearly distinguished from confirmed observations.

1. Target Information

• Target: Kioptrix Level 1
• IP Address: 192.168.162.129
• Hostname: KIOPTRIX
• Workgroup: MYGROUP
• Assessment Phase: Reconnaissance and Vulnerability Assessment

All testing was performed within the designated lab environment.

2. Reconnaissance and Service Enumeration

The initial assessment identified several exposed services, including SSH, HTTP, HTTPS, RPC, and SMB.

The detected software included legacy versions of OpenSSH, Apache, mod_ssl, and OpenSSL.

These findings indicate that the target has an outdated software stack that requires further security assessment. However, identifying an outdated version does not automatically prove that a specific vulnerability can be exploited.

3. Web Server Assessment

3.1 Default Apache Test Page

The web server exposed the default Apache test page.

Default pages may disclose information about the underlying server and indicate that the web server configuration requires further review.

Recommendation: Remove unnecessary default content and minimize avoidable information disclosure.

3.2 PHP Source-Code Disclosure

During testing, a request to /test.php returned an HTTP 200 OK response with the content type text/plain.

The response body contained:

<?php4 print "TEST"; ?>

Instead of returning the expected output of a processed PHP script, the server returned the source code as plain text.

This confirms that the tested file was not processed as expected and that its source code was disclosed.

No credentials, secrets, or sensitive application data were observed in this response. The finding is limited to the tested file and does not establish that all PHP files are affected.

Recommendation: Review the PHP handler configuration, prevent source files from being served as plain text, and verify the correction through controlled retesting.

3.3 Accessible Web Directories

The following paths were accessible during testing:

• /manual/
• /mrtg/
• /usage/

Their accessibility alone does not establish a security vulnerability. However, publicly accessible documentation and monitoring resources may reveal information that supports further reconnaissance.

Recommendation: Review whether these resources need to be publicly accessible and apply suitable access controls.

4. TLS and SSL Assessment

The assessment identified support for SSLv3 and TLS 1.0, legacy cipher suites, and a certificate reported as expired by Nmap.

These observations indicate that the HTTPS configuration requires modernization.

Recommendations:

• Disable obsolete SSL/TLS protocols.
• Configure modern TLS versions and strong cipher suites.
• Replace the expired certificate.
• Reassess the configuration after remediation.

The observed configuration weaknesses do not, by themselves, demonstrate that encrypted traffic was intercepted or decrypted.

5. SMB and RPC Assessment

SMB

TCP port 139 was open, and an anonymous SMB session was accepted during enumeration. Access to IPC$ and ADMIN$ was restricted.

Anonymous session acceptance does not prove unauthorized file access or remote code execution.

Recommendation: Restrict anonymous access, review share permissions, disable unnecessary SMB services, and upgrade unsupported components.

RPC

RPC-related services were observed on TCP ports 111 and 1024.

Further enumeration is required to determine which services are available and whether their exposure creates an exploitable security risk.

Recommendation: Restrict unnecessary RPC exposure and permit only the services required for legitimate operations.

6. Historical Vulnerability Research

During vulnerability research, I identified a historical reference associated with Apache mod_ssl:

• Reference: Exploit-DB ID 21671
• Title: Apache mod_ssl < 2.8.7 OpenSSL — OpenFuck.c Remote Buffer Overflow
• Observed mod_ssl Version: 2.8.4
• Validation Status: Unconfirmed

Although the observed version falls within the version range stated in the reference, version matching alone is insufficient to confirm exploitability.

Further investigation would be required to verify the target's build details, platform characteristics, configuration, and other relevant conditions.

No exploit was executed, and no shell or root access was demonstrated during the documented assessment.

This reference is therefore classified as a potential vulnerability lead rather than a confirmed compromise.

7. Findings Summary

The assessment produced the following observations:

• Legacy server software was identified.
• PHP source code was disclosed by the tested /test.php endpoint.
• SSLv3 and TLS 1.0 support were observed.
• Legacy and weak cipher suites were identified.
• The TLS certificate was reported as expired.
• Anonymous SMB session acceptance was observed, while access to the examined administrative shares was restricted.
• RPC services were exposed and require further review.
• A historical mod_ssl vulnerability reference was identified but remains unverified.

Successful exploitation and privilege escalation have not been demonstrated.

8. Remediation Priorities

The recommended remediation actions are:

1. Upgrade legacy software

Replace unsupported server components with supported versions and apply appropriate security updates.

2. Correct PHP handling

Configure server-side PHP processing correctly and prevent application source files from being exposed as plain text.

3. Strengthen TLS configuration

Disable obsolete protocols, remove weak cipher suites, and replace the expired certificate.

4. Reduce unnecessary service exposure

Restrict anonymous SMB access, review share permissions, and disable or filter unnecessary RPC services.

5. Validate the fixes

Repeat the relevant checks and retain evidence demonstrating whether each issue has been resolved.

9. Lessons Learned

This assessment reinforced several important penetration testing principles:

• Reconnaissance helps establish the target's attack surface.
• Software version detection is an investigative starting point, not proof of exploitability.
• Security findings must be supported by evidence.
• The scope of a finding should match what was actually observed.
• Vulnerability research, exploitation, and privilege escalation must be documented as separate stages.
• Remediation recommendations should address the underlying weakness.

Conclusion

The initial assessment of Kioptrix Level 1 identified legacy services, PHP source disclosure affecting the tested file, outdated TLS configuration, and SMB/RPC exposure requiring further investigation.

A historical mod_ssl vulnerability reference was also identified, but its applicability to the target remains unconfirmed.

This article documents the findings supported by the available evidence. Successful exploitation, shell access, and root access have not been demonstrated.

The next stage is to validate the outstanding vulnerability hypotheses, conduct any additional authorized testing, and document the results with reproducible evidence.

Disclaimer: This write-up documents testing in a controlled lab environment for educational purposes. Always obtain authorization before assessing systems you do not own or administer.